Improvement in safety-paper for bank-checks or other documents of value



UNITED STATES PATENT FFIGE.

JOHN HEN'DBICHS, OF NEW YORK, N. Y.

IMPROVEMENT lN SAFETY-PAPER FOR BANK-CHECKS OR OTHER DOCUMENTS 0F VALUE.

Specification forming part of Letters Patent No. 223,] 36, datedDecember 30, 1879 application filed November 8, 1879.

To all whom it may concern Be it known that 1, JOHN HENDRIOHS, of thecity, county, and State of New York, have invented a new and usefulImprovement in Safety Paper for Bank-Checks or other Documents of Value,which invention is fully set forth in the following specification.

This invention relates to a safety-paper for bank-checks or otherdocuments of value produced by subjecting ordinary paper first to theaction of an aqueous solution of sulphate of copper and carbonate ofammonia, and then to the action of an alkaline solution of cochineal orother equivalent coloring-matter mixed with alum and glycerine.

In carrying out my invention, I take one pound of sulphate of copper orblue-stone and one pound of carbonate of ammonia, dissolve both in abouteight gallons of water, then dip any kind of paper into it, and thepaper will turn light blue. Hang it up until it is dry. W'hen the paperis dry, I dip the same into a solution of eight gallons of water, onepound of cochineal, carmine, or carmine-lake, or any other color whichis made out of cochineal,-

two ounces of carbonate of potash or any other alkali, half an ounce ofalum, and two pounds of glycerine. By the last-named process the tint orcolor of the paper will be changed to a light gray, and, after beingdried, will be ready for use. In writing on it any ink may be used. Whenany acid is applied to it for the purpose of removing the ink, the paperwill change its color during the process, and should any attempt be madeto restore the original color it will again change, and cannot berestored in any wayto its original color without showing.

The advantages of my safety-paper are as follows: First, it can beprinted on in a wet or dry state; second, any ink can be used forwriting on it 5 third, water will not affect the ink; fourth, it willnot fade in any atmosphere or climate; fifth, the color changes'firstwhen acid is used, and changes to another color if one tries to restorethis color; sixth, it can be tinted or colored with any color or design,and can be written on in any way, wet or dry; seventh, it can be usedwith great advantage for bank checks, bonds, or other documents ofvalue, also for revenue-stamps, or all other articles of a similarnature.

What I claim as new, and desire to secure by Letters Patent, is-

l. The within-described'process of producing safety-paper by dippingordinary paper in any aqueous solution of sulphate'of copper andcarbonate of ammonia and then drying the same, and finally dipping it inan alkaline solution of cochineal or other equivalent coloring-mattermixed with alum and glycerine, substantially as described.

2. As a new article of manufacture, a safetypaper produced by subjectingordinary paper first to the action of an aqueous solution of sulphate ofcopper and carbonate of ammonia, and then to the action of an alkalinesolution of cochineal or other equivalent coloringmatter mixed with alumand glycerine.

In testimony that I claim the foregoing I have hereunto set my hand andseal this 6th day of November, 1879.

JOHN HENDRIOHS. [L. s.]

Witnesses: I

HENRY M. WALKER, W. T. WOOD.

